JPH07183432A - Semiconductor package provided with heat sink - Google Patents

Abstract

PURPOSE:To improve the cooling efficiency of a package at the time of air- cooling, by making the sizes of many plate fins arranged horizontally on the side surface of a strut be smaller in the lower part. CONSTITUTION:An aluminum heat sink 7 is bonded to the upper surface of a chip mounting board 2 by using heat sink fixing material. As to the heat sink 7, a strut is stood in the central part, and many plate type fins 7a are fixed horizontally to the periphery of the strut. The sizes of the plate fins 7a are smaller in the lower part. Hence, as to the air sent from a fan, the quantity of escaping air toward above the heat sink 7 is decreased, and on the contrary, the quantity of flowing air through the fin gaps of the heat sink 7 is increased. As the result, the practical air flow velocity in the fin gaps becomes large as compared with the conventional. heat sink 7 whose fin size is equal, so that the heat dissipation efficiency is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat sink-equipped semiconductor package for mounting chips such as IC chips and LSI chips.

[0002]

2. Description of the Related Art In recent advanced semiconductor devices, the speed and power product per gate are gradually decreasing, and the area occupied per gate is gradually decreasing due to the development of fine processing technology. Therefore, the semiconductor chips tend to be faster and more highly integrated. On the other hand, the package for protecting the semiconductor chip and improving the reliability has also been developed into an area in which a high level mounting technology is required by introducing a bonding technology for the semiconductor chip. Along with this, in recent computer devices and the like, semiconductor elements integrated into LSI and various semiconductor packages for mounting high-density and miniaturized LSI chips are gradually being used in order to improve processing performance and reliability of the device. It has come to be adopted.

By the way, as the degree of high integration of the device increases, the power consumption of the semiconductor chip also increases. Therefore, an LSI chip with high power consumption is mounted on a package such as ceramic, which has a higher thermal conductivity than plastic, and further, there is a limit to cooling the LSI chip only by heat dissipation by the board.

Therefore, in the conventional semiconductor package mounting the above-mentioned high-speed and highly integrated LSI chip, from the viewpoint of cooling against heat radiation from the LSI chip,
A heat sink made of a material having high heat dissipation efficiency such as aluminum or copper is integrally fixed to the upper surface of the semiconductor package with solder or an adhesive having excellent thermal conductivity so as to radiate heat.

FIG. 3 is a perspective view of an example of a conventional semiconductor package with a heat sink. In the figure, 1 is a case,
Reference numeral 5 is a pin, and 7 is a heat sink.

FIG. 4 is a sectional view of an example of a conventional semiconductor package with a heat sink. In the figure, reference numeral 1 denotes a case, on which a chip mounting plate 2 is adhered with a material having good thermal conductivity. Further, the chip 3 is mounted on the lower surface of the chip mounting plate 2 using a chip fixing agent. The chip 3 is connected to the wiring on the case 1 and the wiring member 4. A plurality of pins 5 are attached to the lower side of the case 1. A cap 6 is adhered to the lower surface of the case 1 so as to cover the chip 3 and keeps the inside airtight. A heat sink 7 is bonded to the upper surface of the chip mounting plate 2 with a heat sink adhesive. The heat sink 7 is
A pillar stands vertically in the center, and a large number of plate-shaped fins are arranged horizontally around the pillar. Currently, a semiconductor package with a heat sink having such a structure is manufactured, and it is cooled by natural air cooling or an air cooling fan mounted inside the apparatus.

[0007]

However, the semiconductor package with a heat sink having the above-mentioned structure has a drawback that the heat dissipation efficiency of the heat sink is not so good and a sufficient cooling effect cannot be obtained. This allows
There is a problem that the operating speed of the device decreases due to the temperature rise of the chip itself.

It is an object of the present invention to provide a highly reliable semiconductor package with a heat sink which has a sufficient heat dissipation effect even if a highly integrated LSI chip which generates a large amount of heat is mounted.

[0009]

A semiconductor package with a heat sink according to the present invention is a semiconductor package with a heat sink, which has a case and a heat sink.
The case is for accommodating chips, and the hole serving as a chip storage space is covered with a chip mounting plate and a cap,
The chip is adhesively fixed to the lower surface of the chip mounting plate or the upper surface of the case, the heat sink is fixed to the chip mounting plate, and the heat sink is aligned with the pillar vertically standing in the center and its side surface. It is characterized by a structure in which a large number of fins are arranged in a horizontal state, and the size of the fins becomes smaller as it goes downward.

[0010]

When the degree of high integration of elements, such as VLSI, increases, the power consumption of the semiconductor chip increases. Therefore, the LSI chip with high power consumption can reduce heat dissipation efficiency from the viewpoint of cooling against heat dissipation from the LSI chip. A heat sink made of a highly expensive aluminum or copper material is integrally fixed to the surface opposite to the fixing surface of the LSI chip by a solder or an adhesive having excellent thermal conductivity to radiate heat. There are various shapes of the heat sink, and plate fin type, fin horizontal type, pin fin type and the like are used.

In the semiconductor package with a heat sink according to the present invention, the structure of the heat sink has a pillar standing in the center,
A large number of plate-shaped fins are horizontally arranged on the side surface, and the size of the fins becomes smaller toward the bottom. Therefore, the amount of air sent from the fan escapes above the heat sink, and the amount of air passing through the fin gap of the heat sink increases. Therefore, the substantial air flow velocity in the fin gap becomes larger than that of the conventional heat sink in which all the fins have the same size, and therefore the heat radiation efficiency becomes large.

[0012]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a perspective view showing an example of a semiconductor package with a heat sink of the present invention. In the figure, 1 is a case, 5 is a pin, and 7 is a heat sink.

FIG. 2 is a sectional view of an example of a semiconductor package with a heat sink according to the present invention. In the figure, 1 is an alumina case having a flat plate shape and a hole in the center, and a chip mounting plate 2 fitted on the center hole of the case 1
Are glued together. Further, a chip 3 is mounted below the chip 3 by using a chip fixing agent. Reference numeral 5 denotes a plurality of pins for connecting the chip 3 to a board. The pins 5 are provided upright on the peripheral portion of the lower surface of the case 1. A connection pad for connecting the pin 5 and the chip 3 is provided around the central hole of the case 1, and the connection pad and the pin 5 are electrically connected to each other through the surface or the inner layer of the case 1. There is. The terminal portion of the chip 3 is connected to the connection pad connected to the pin 5 by the wiring member 4 such as a wire. A cap 6 is adhered to the lower surface of the case 1 by an adhesive agent such as low melting point glass so as to cover the chip 3, and the inside is kept airtight. An aluminum heat sink 7 is bonded to the upper surface of the chip mounting plate 2 with a heat sink adhesive. The heatsink 7 has a pillar standing in the center, and a large number of plate-shaped fins 7a are horizontally mounted around the pillar.

According to the present invention, the thermal resistance of a package having a heat sink whose structure is such that the plate fins become smaller as it goes down and a conventional package having a heat sink having a structure in which the plate fins have the same size are mounted. Compared in the experiment. In the package of the present invention, the flow velocity of the air forcedly cooled by the external fan is 1 m / s.
At that time, the thermal resistance was 2.0 ° C./W. On the other hand, in the conventional package, the air velocity by the external fan is 1m.
/ S, the thermal resistance was 2.8 ° C / W. From the above,
It was found that the package with the heat sink having a structure in which the plate fins have a smaller size has lower thermal resistance than the package with a heat sink having a structure in which all the plate fins have the same size.

In the above embodiment, the example of aluminum was used as the heat sink material, but it is not limited to this, and it is clear that the effect of the present invention can be sufficiently satisfied if the material has good thermal conductivity. is there.

[0017]

As described above, according to the present invention,
Since it is possible to suppress the temperature rise of the chip and the ceramic package due to heat generation when energized, it is possible to provide a high-speed operation and highly reliable semiconductor package.

[Brief description of drawings]

FIG. 1 is a perspective view of a semiconductor package with a heat sink showing an embodiment of the present invention.

FIG. 2 is a sectional view of a semiconductor package with a heat sink showing an embodiment of the present invention.

FIG. 3 is a perspective view of an example of a conventional semiconductor package with a heat sink.

FIG. 4 is a sectional view of an example of a conventional semiconductor package with a heat sink.

[Explanation of symbols]

 1 case 2 chip mounting plate 3 chip 4 wiring member 5 pin 6 cap 7 heat sink 7a fin

Claims (1)

[Claims] 1. A semiconductor package with a heat sink having a case and a heat sink, a case for housing a chip, a chip mounting plate and a cap forming a space for housing the chip together with the case, and the chip mounting plate. A semiconductor package with a heat sink, comprising a heat sink having a plurality of fins, the size of the fins becoming smaller as going downward around a vertical column at the center.